mehren



(No Model.)

J. F. MEHREN.

KEY.

110.415.4112. Patented Nov. 19, 1889.

527/627 Zak Jaaozj' Mam- ' N. PEIERS. Photo-Lithographer. Washington. D. c.

UNITED STATES PATENT OFFICE.

JACOB F. MEHREN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO PHILIP C. DYRENFORTH AND IVILLIAM H. DYRENFORTH, BOTH OF SAME PLACE.

KEY.

SPECIFICATION forming part of Letters Patent No. 415,412, dated November 19, 1889.

Application filed November 23, 1888- Serial No. 291,661. (No model.)

To all whom it may concern:

Be it known that I, JACOB F. MEHREN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Keys, of which the following is a specification.

My improvement relates to the class of duplex keys for use in shooting the bolts of looks; and it relates particularly to a key of the class named, having a stem provided to Ward each end which enters the lock with notches or notched webs adapted to fit diiferent locks.

Instances are common where, for the sake of additional security or other reason s, two separate locks, with wards differently arranged, are employed for a single door or barrier, or for two doors or barriers which are closely relatedas, for instance, the inner and outer doors of a vestibule, or of any compartment employing two doors, or any receptacle having an internal compartment to be locked such, for example, as a desk or secretary 2 5 which is itself to be locked and is provided with an internal drawer or compartment also provided with a lock.

One of the more important instances of the use of my improvement is its application to 0 the modern system of police and fire signals in which street-boxes are employed. In these one door has to be opened to gain access to the telephone signaling apparatus, while a separate door, usually in a small metal box,

5 has to be opened to permit access to the firesignaling mechanism.

My improvement consists in providing a duplex key with a suspension-ring loosely surrounding and longitudinally movable on the stem; and it further consists in having the stem, with the suspension-ring upon it, hollow throughout its entire extent.

In the drawings, Figures 1 and 2 illustrate in sectional elevation different forms 4 5 of keys of my improved construction provided with bits at opposite ends; and Fig. 3 is a flat key, in elevation, provided with notches at opposite ends.

A is the stem or body of the key, which may be substantially round and of equal diameter throughout its length, as in Fig. 1, or of unequal diameters toward its opposite ends,

as shown in Fig. 2, to fit key-holes with eyes of different sizes, or it may be fiat, or substantially so, throughout part of its length, or its entire length, as shown in Fig. 3.

In Figs. 1 and 2 bits B are provided at opposite ends of the stem A, and have notches to adapt them to fit the different locks for which they are designed. A key of this kind is provided with a suspension-ring if, having an eye t, and loosely encircling the stem to permit of its being slid back and forth, thereby to avoid impediment to the insertion into the lock of the stem to its full length, up to the web at the opposite end, if required. By means of the eye t the key may be attached to a key-ring. The kind of key which for the purpose of fitting over a post in a lock is ordinarily provided with a socket in the end I prefer to make hollow throughout, as shown in Figs 1. and 2, whereby foreign matter, which gets into the socket and tends to clog the key, may be easily forced from one end out through the other.

The flat key (shown in Fig. 3) is for the sake of illustrating more diversified forms of my invention, provided at opposite ends with notches to fit locks dilferent in construction, and the suspension-ring with which it is provided is movable back and forth by being confined in a longitudinal slot in the stem of the key, as shown.

WVhat I claim as new, and desire to secure by Letters Patent, is

1. A duplex key comprising a stem provided toward each end with a bit and having a suspension-ring t loosely secured to the stem and movable back and forth thereon, substantially as and for the purpose set go forth.

2. A duplex key comprising a cylindrical stem hollow throughout its entire length and loosely encircled by a suspension-ring I, movable back and forth on the hollow stem, 5 substantially as and for the purpose set forth.

JACOB F. MEHREN.

In presence of-- M. J. BowERs, J. W. DYRENFORTH. 

